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    <title>Document</title>
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    <script>

        for (var i = 1; i < 13; i = i + 4) {
            console.log(i);
        }
        // 分析执行流程 1, 5 ,9 

        for (var i = 1; i < 10; i = i + 3) {
            i = i + 1;
            console.log(i);
        }

        // 2,6,10,

        for (var i = 1; i <= 10; i++) {

        }
        console.log(i); // 11


        for (var i = 1; i < 7; i = i + 3) {

        }
        console.log(i); // 7

        // for (var i = 1; i > 0; i++) {
        //     console.log(i);
        // }
        // 死循环 永远符合条件

    </script>
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